Department of Ophthalmology, University Hospital Basel, University of Basel, Basel, Switzerland.
J Ocul Pharmacol Ther. 2011 Dec;27(6):577-80. doi: 10.1089/jop.2011.0062. Epub 2011 Sep 1.
To determine the possibility of plasma citrate as a biomarker in patients with glaucoma.
Twenty-one consecutive Caucasian patients with glaucoma and 21 sex- and age-matched controls were investigated. Plasma citrate, plasma creatinine, urine citrate, and urine creatinine were analyzed by ion chromatography. Mean (±standard deviation) concentrations and the calculated fractional citrate excretions were compared using the Mann-Whitney test. Sensitivity and specificity to detect glaucoma using plasma citrate levels were calculated.
The mean plasma citrate (104.8±23.2 vs. 128.2±31.1 μmol/L; P=0.01) concentrations were significantly lower among the patients with glaucoma, whereas the mean urine citrate concentrations (1.7±0.9 vs. 2.8±1.9 μmol/L; P=0.07) were slightly lower. Mean plasma and mean urine creatinine concentrations showed no significant differences (plasma creatinine: 63.0±16.7 vs. 63.4±15.5 μmol/L; P=0.72; urine creatinine: 9.6±5.1 vs. 11.5±8.4 μmol/L; P=0.67). The calculated fractional citrate excretions were also not different with 12.1% versus 13.6% (P=0.37). Setting the cut-off limit at 110 μmol/L, the plasma citrate level evaluation would have a sensitivity of 66.7% and a specificity of 71.4% to detect glaucoma.
In this masked study, plasma citrate levels were significantly decreased in Caucasian patients with glaucoma giving the possibility to use them eventually as a biomarker. The kidney function was normal in both groups, leaving the etiology of this hypocitraemia yet unexplained.
确定血浆柠檬酸盐是否可作为青光眼患者的生物标志物。
连续纳入 21 例白种人青光眼患者和 21 例性别、年龄匹配的对照组。通过离子色谱法分析血浆柠檬酸盐、血浆肌酐、尿柠檬酸盐和尿肌酐。采用 Mann-Whitney 检验比较两组的平均值（±标准差）浓度和计算的柠檬酸盐排泄分数。使用血浆柠檬酸盐水平计算检测青光眼的敏感性和特异性。
青光眼患者的平均血浆柠檬酸盐（104.8±23.2 与 128.2±31.1 μmol/L；P=0.01）浓度明显较低，而平均尿柠檬酸盐浓度（1.7±0.9 与 2.8±1.9 μmol/L；P=0.07）略低。平均血浆和平均尿肌酐浓度无显著差异（血浆肌酐：63.0±16.7 与 63.4±15.5 μmol/L；P=0.72；尿肌酐：9.6±5.1 与 11.5±8.4 μmol/L；P=0.67）。计算的柠檬酸盐排泄分数也无差异，分别为 12.1%与 13.6%（P=0.37）。以 110 μmol/L 为截断值，血浆柠檬酸盐水平评估对检测青光眼的敏感性为 66.7%，特异性为 71.4%。
在这项盲法研究中，白种人青光眼患者的血浆柠檬酸盐水平显著降低，有可能最终将其用作生物标志物。两组的肾功能均正常，这种低柠檬酸血症的病因仍未得到解释。
